We report a record low threshold current of 1.55-μm vertical-cavity surface-emitting laser (VCSEL). Thin-film wafer-fusion technology enables InP-based buried heterostructure VCSELs to be fabricated on GaAs-AlAs distributed Bragg reflectors. Threshold current density is independent of mesa size, and a 5-μm VCSEL exhibits a threshold current as low as 380 μA at 20/spl deg/C ...
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We report continuous-wave room temperature operation of a GaAsSb-GaAs quantum-well vertical-cavity surface-emitting laser near 1.3 μm. The device is pumped with 674 nm light and provides 1-QmW total optical output at 1280 nm with 40% differential quantum efficiency. We describe the spatial, angular and spectral properties of the laser. This device sets a record for long wavelength with hig...
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GaAs-AlGaAs quantum-well (850 nn) vertical-cavity surface-emitting lasers, with lateral current injection and shallow implanted apertures, show small signal modulation bandwidths of at least 11 GHz and large signal data rates of at least 10 Gb/s. The devices achieved a maximum output power of 2.1 mW, with a threshold current and voltage of 1 mA and 1.71 V, respectively. The shallow implantation st...
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Using a hybrid ion implanted/selectively oxidized device structure, we report high-power single-mode operation of an 850-nm vertical-cavity laser. Under continuous-wave operation, >4 mW of single-mode power with 45 dB of side-mode suppression is achieved. The spectral behavior under pulsed modulation is determined to be influenced by thermal lensing. When biased to threshold, single-mode operation...
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We present theoretical and experimental results on the scaling properties of bipolar cascade vertical-cavity surface-emitting lasers with respect to active region stacking and out-coupling mirror reflectivity. The measurement results at around 980-nm wavelength confirm the theoretically expected behavior of an almost linear increase in slope efficiency and a reduction in threshold current density ...
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For simplifying the fabrication and operation of multiwavelength laser arrays, sampled grating distributed Bragg reflector (SGDBR) lasers are utilized to form the arrays, where the two SGDBR mirrors of each laser are fabricated on waveguides of different thicknesses. Fabrication of such laser arrays requires a single step of holographic exposure to realize the gratings. The lasers in an array can ...
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A low-noise high-power source incorporating a polarization-maintaining erbium-Brillouin fiber amplifier is presented. The output noise power is analyzed and a theoretical noise spectral density is determined. Shot-noise-limited performance is predicted and experimentally achieved within the 1-8-GHz-offset frequency range. The polarization extinction ratio was measured as 25 dB.
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We analyze the recently proposed serial topology of a wide-band erbium-doped fiber amplifier (EDFA) covering both the C- and L-bands and compare it with the parallel configuration of C-band and L-band amplifiers. The analysis is based on an application of a comprehensive large-signal numerical model, which takes into consideration propagation of wavelength-division multiplexing (WDM) signals, bidi...
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We propose a flexible method for flattening the gain profile of an erbium-doped fiber amplifier (EDFA). The method is based on a high-birefringence fiber loop mirror (HiBi-FLM), which contains a number of high-birefringence fiber sections and polarization controllers. We show that, by setting the polarization controllers properly, the reflection spectrum of the loop mirror can be adjusted to compe...
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A simplified model to calculate the small-signal optical gain and noise figure of a multiwavelength backward-pumped fiber Raman amplifier under the triangle Raman profile approximation is developed for the first time. The application of the developed model in pump optimization design for flattening the gain spectrum profile is also discussed.
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A simulated annealing algorithm is adopted to give an automatic pump configuration in laser-diode backward-pumped-distributed fiber Raman amplifiers. The demonstration of the optimization process of wavelengths and powers in an optical-fiber Raman amplifier using four laser-diode pumps is presented. The resulting gain ripple is less than 2.6 dB in respect to the 30 dB average gain in the amplifica...
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A technique for stabilizing the center frequency of a short cavity DBR fiber grating laser is reported. This method employs an all-fiber unbalanced-arm scanning Michelson interferometer as a frequency discriminator. Long-term frequency fluctuation of the tested fiber grating laser was improved from /spl plusmn/480 MHz to less than /spl plusmn/30 MHz.
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Electroabsorption modulator (EAM)-distributed feedback (DFB) modules with record-high bandwidth of 41 GHz have been developed. 40-Gb/s nonreturn to zero (NRZ) operation with 12-dB extinction ratio and -1.6-dBm average output power have been successfully achieved by optimizing the EAM length and detuning. A clearly opened eye diagram was maintained even after 80-km nonzero dispersion shifted fiber ...
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We propose and analyze a new all-optical nonlinear switch. The device is based on cross-phase modulation (XPM)-induced temporary frequency shift upon co-propagation of signal and control pulses with walkoff, and on the filtering effect of a fiber Bragg grating (FBG). Very high ON/OFF contrast with practically no pulse distortion can be achieved with moderate switching power. The new device possess...
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Collision-induced power jitter is theoretically and numerically examined in dispersion-managed wavelength-division multiplexed optical soliton transmission systems. The variational method is mainly used to develop a time efficient jitter calculation approach. The power jitter causes a serious problem for a singly periodic dispersion managed line having almost zero average dispersion, which can be ...
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We investigate the polarization evolution for both signal and noise in two 107-km recirculating loops with polarization-dependent loss per round-trip of 0.35 dB and less than 0.1 dB, respectively. When the system is optimized, in the first case, both signal and noise are polarized, while in the second case, the signal tends to depolarize due to the noise. We experimentally measured and theoretical...
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We present the design for an add-drop multiplexer using a multimode interference device that supports two modes, and incorporates a Bragg grating. This device only exploits the dispersive aspects of the grating in transmission. The grating induces a wavelength-dependent phase difference between the modes inside the structure, effectively inverting the interference pattern at the output of the devi...
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We present a previously unknown equivalence relationship between the spectral transfer functions of arrayed-waveguide gratings and fiber Bragg gratings (FBGs). We find that both devices can be characterized using a functionally identical Fourier transform (FT) integral; the single difference being that the FT lies within a simple hyperbolic function for the FBG case. Thus, the mode of operation of...
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We report the fabrication and characterization of a one-dimensional acoustic cavity made on a tapered single-mode optical fiber with two acoustic mirrors. The mirrors are acoustic Bragg gratings formed by modulating the fiber diameter periodically. The cavity exhibits resonances with quality factors of around 300. Higher Q factors are achievable by increasing the number of periods in the gratings....
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Deep ultraviolet optical fibers are fabricated using modified SiO/sub 2/ glasses containing 2000-ppm fluorine for the clad and 200 ppm for the core. The transmission at 193 nm is improved to more than 60%/m by optimizing the fiber drawing condition. The H/sub 2/-inpregnation into the fiber suppresses the degradation of the transmission by irradiation of ArF excimer laser (50 mJ/cm/sup 2//pulse). F...
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Holey fibers are shown to have an ideal geometry for efficient parametric processes due to their tailorable modal properties. These fibers can have the additional advantage of single-mode operation at all the interacting wavelengths. We demonstrate theoretically that by appropriate choice of holey fiber geometry, these fibers can be up to four orders of magnitude more efficient for second harmonic...
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A new tunable dispersion compensator that does not suffer from higher order dispersion is reported. The device consists of two quadratically chirped fiber Bragg gratings, each with linear strain actuators. The module has a tuning range of 500 ps/nm and a bandwidth of 0.5 nm. In a 40-Gb/s return-to-zero system, the dispersion penalty tolerance is extended from 100 to 600 ps/mm.
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In this letter, we report on up to 300-Gb/s real-time all-fiber-based optical eye-diagram measurements with 1.6-ps temporal resolution and 5-Hz refresh rate by all-optical sampling using parametric amplification in a short (50 m) highly nonlinear fiber. This represents, to the best of our knowledge, the highest bit-rate eye-diagram measurement so far, as well as the first demonstration of a fiber-...
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Aims & Scope

This letters journal addresses all aspects of the IEEE Photonics Society Constitutional Field of Interest with emphasis on photonic/lightwave components and applications, laser physics and systems and laser/electro-optics technology.